1. Field of the Invention
The present invention relates to a vehicle having an electronic continuously variable transmission (CVT) and an idle speed control device, and a control device and method thereof.
2 Description of Related Art
A CVT that performs idle speed control (ISC) is known (for example, JP-A-2004-19740). ISC typically uses an ISC valve to change a passage area of a by-pass passage to increase or decrease the amount of intake air to an engine, thus adjusting the rotational speed of the engine when idling (idle rotational speed).
An electronic CVT (ECVT) is also known. In an ECVT, the transmission gear ratio can be adjusted regardless of the rotational speed of the engine. Therefore, ECVTs are widely used in vehicles such as scooters.
When the ISC of JP-A-2004-19740 is applied to a vehicle having an ECVT, the speed of the vehicle may problematically increase even if the rider does not open the throttle. In other words, the speed of the vehicle may increase regardless of the rider's intention to decrease speed. Drivability is thereby not desirable.